1. Field of the Invention.
The invention relates to hinge pins and retention sleeves used in chain link assemblies.
2. Prior Art.
The use of hinge pins to connect half-links of chains is widely known. In typical applications, the chain half-links are U-shaped with aligned passages near a top of the U-shaped half-links to receive a hinge pin. An adjoining half-link has a similar or identical geometry. When a hinge pin passes through the passages of adjacent half-links, the adjacent half-links are thereby connected together. Various methods have been used to secure the hinge pins with respect to the chain half-links, including the use of C-clamps and sleeves.
There have been many inventions for hinge pins for chain link assemblies. For example, Devonshire et al. (U.S. Pat. No. 2,972,223) discloses a joiner link assembly having a collar or sleeve to receive a joining pin 12, having circumferentially spaced and longitudinally extending flutes 35. The assembly permits the pin to be easily started into the collar bore. Manney et al. (U.S. Pat. No. 3,373,560) discloses a joiner link with a pin 26 having main diameter portions 46 and 48 and a reduced diameter portion 44. A locking clip 40 surrounds the reduced diameter portion. In one embodiment, a pair of washers surrounds the locking clip 40 on the pin.
Fink (U.S. Pat. No. 3,828,560) discloses a coupling link having a pin 30 with an annular groove 36. A spring clip 24 locks the pin 30 in an axial position.
Crook, Jr. (U.S. Pat. No. RE 27,260) discloses a coupling link having identical like halves each provided with mating ears. A coupling pin 22 of constant outside diameter is received in a longitudinally split sleeve having a lesser nominal diameter than the pin.
Bergman (U.S. Pat. No. 3,134,221) discloses a coupling with a pin 4 having a spring 9 which resides in a reduced diameter groove 7. Additional grooves 8 on each side of the groove 7 receive the spring 9 if the pin 4 is dislodged.
Mason (U.S. Pat. No. 3,241,309) discloses a joiner link assembly having a pin 22 with an enlarged knob-shaped central portion 30. C-shaped locking sleeves surround the pin on each side of the knob-shaped central portion 30.
Other patents deemed pertinent to the present invention are listed below.
PATENTEE U.S. PAT. NO. Fink 3,899,873 Albertini 4,179,878 Crook, Jr. 4,106,284
While there have been other chain link assemblies having hinge pins and retention sleeves, these assemblies have had many problems. For some existing hinge pins and sleeves, a C-shaped sleeve has been crimped onto the pin along the length of the pin, which results in eventual loosening of the sleeve.
For other hinge pins and sleeves of the existing art, for which a pin and sleeve have reduced cross-sections such as the device shown in FIG. 1, these reduced cross-sections are located near the high-force areas where the pin engages a half-link. Because the forces acting on the pin and sleeve are greater near the half-links, it is undesirable to have reduced cross-sections in these areas. The resultant stresses acting within the pin and sleeve are inversely proportional to the areas of the cross-section of the pin and sleeve. As a result, the pin and sleeve are more likely to fail.
Another problem with existing hinge pins and sleeves, they are composed of many parts which are difficult and cumbersome to assemble.
It is, therefor, a principal object and purpose of the present invention to provide a retainment device for a hinge pin to connect chain half-links together.
It is a further object and purpose of the present invention to provide a hinge pin with a retainment device to laterally position the hinge pin with respect to the chain half-links.
A still further object and purpose of the present invention is to provide a hinge pin and retainment device that are each unitary to facilitate installation of the hinge pin and sleeve in a coupling assembly.
Another object and purpose of the invention is to provide a hinge pin and retainment device in which reduced cross-sections are located near the center of the hinge pin and sleeve away from the high-stress areas near the chain half-links.
Another object and purpose of the invention is to provide a hinge pin and retainment device in which the hinge pin annular notch has a blended, transition radius to remove high stress concentrations.
Another object and purpose of the invention is to provide a retainment device that, after installation is completed, remains in an un-stressed state and therefore is not susceptible to failure modes that are associated with steel components that are subjected to continual stress.